1. Field of the Invention
The present invention relates to static wood structures. More particularly, the present invention relates to a method for making a laminated wood product.
2. Background Art
A variety of laminated wood beams are used in construction work today as joists, girders, posts, columns or other structural pieces. Laminated wood beams are known to be stronger, more resistant and more dimensionally stable than continuous wood beams. Unfortunately, the fabrication of traditional laminated beams requires the use of wood members of dimensions and quality that have become increasingly harder to obtain due to the fact that nowadays the trees available are a lot smaller than they once were. Thus, the wood members are often cut from trees of relatively small diameter, such as trees from plantation or northern forests, thereby producing members of low grade, small dimensions and with a high proportion of flash.
Also, the cutting of wood for various elements required in construction work generates a great quantity of pieces of small dimensions, difficult to reuse thus usually considered as waste. This high proportion of wasted material greatly increases fabrication costs.
Accordingly, a number of alternative laminated wood products methods have been developed in order to be able to use smaller wood members and/or wood members of lower grade. One example of such a product is presented in U.S. Pat. No. 4,568,577 issued Feb. 4, 1996 to Fischetti, where squared timbers of uniform thickness are joined edge to edge and end to end in order to form a laminated structure with at least one longitudinal void. While this configuration allows for the recycling of timbers of small length by joining them end to end through a pencil joint, it does not allow the use of timbers of varying thicknesses. Moreover, defects such as flash must be removed before assembling the timbers, thereby reducing the proportion of waste material that can be reused.
A number of alternative methods gave also been developed to produce laminated wood products. U.S. Pat. No. 6,446,412 issued Sep. 10, 2002 to Mathis presents a method of making glulam wood beams using strips of planks of identical thickness glued side to side. Careful planning in the placement of the planks of various widths is needed to avoid aligned joints in the beam causing beam weakness. If the joints between planks are aligned, a strip can be cut from the beam perpendicularly to the original strips and then attached thereto to reinforce the beam. However, this additional strip greatly increases the time and costs of manufacturing by augmenting the number of steps in the process.
CA Patent Application No. 2,350,380 filed Jun. 13, 2001 by Grenier presents a method for making a lamellated wood product of high mechanical properties from wood slats of uniform thickness. The wood slats are bonded end to end to a desired length and edge bonded into a panel, the panel is cut into smaller panels of identical width, the small panels are face bonded to form a beam, the beam is cut to form smaller beams, and the small beams are cut into lamellated wood product. This process requires numerous steps in order to obtain the final product. Moreover, the requirement of uniform thickness prevents the use of slats containing defects such as flash.
Accordingly, there is a need for a method of making laminated wood beams that requires a minimum of steps, while easily integrating the use of potential waste material such as small wood members of non standard dimensions and wood members containing flash.